With the rapid development of Internet technologies, a system whose computing resources are virtualized has been proposed and is developing gradually, because virtualization technology can bring enterprises practical benefits in resource sharing and operation cost reduction, more and more enterprises are currently selecting a virtual cloud platform as their service bearer.
Along with the large-scale application of virtualization technology, the security of a system starts to gain great attention. The conventional security precautions are started from a boundary protection access side, that is, the user name and the password of a user are authenticated or a certificate issued by a Certificate Authority (CA) center is verified when the user access to a system, thereby guaranteeing the security of the user and an access channel.
However, in practical applications, in the inside of a virtual cloud platform, a physical cloud computing host is generally isolated from a virtual cloud computing machine by a Virtual Local Area Network (VLAN); through a VLAN isolation technology, the network devices in a network system can be divided into a plurality of virtual working groups, and the network devices in different groups are isolated from each other on the second layer. As the VLAN isolation technology is based on the isolation of the second layer from the third layer, different network users and network resources can be grouped, and the data exchange between the network devices of one group can be isolated from that between the network devices of another group by a switcher supporting the VLAN technology, thereby guaranteeing the security of a network. This mode allows the users on the same VLAN to communicate with each other, but the users on different VLANs are disconnected from each other on a data link layer and therefore can only access each other through three layers of routers.
The VLAN isolation technology, although capable of guaranteeing the isolation of physical devices, only allows a single server to be fully and synchronously opened for a plurality of VLAN groups or only opened for a certain VLAN group, incapable of limiting a specific user. Moreover, in practical applications, a server plays the roles of various kinds of servers to provide different services for the users in a plurality of VLAN groups, this causes the following safety hazard: a virtual cloud system based on the isolation technology is likely to be attached and cracked by some malicious people or organizations, and even worse, a virtual cloud computing machine may be illegally created and controlled by malicious people or organizations, thus threatening the safety of a system.